A conventional vehicle closure assembly, such as a hood assembly, generally consists of a stamped sheet metal hood outer, a stamped hood inner, hood latch, hinge reinforcements, and other reinforcements as needed for strength and stability required for the functionality of the hood assembly. Reinforcements are secured to the hood inner by welding, structural adhesives, threaded fasteners, rivets or similar joining techniques to assemble a hood inner sub-assembly. The hood inner sub-assembly may be joined at the periphery with the hood outer using structural adhesives and a hem flanging process. The large number of component parts assembled together to make a vehicle closure member adds to the cost and complexity of the manufacturing process. The components of a hood assembly may be made from SMC, carbon fiber, steel, aluminum or other metals resulting in problems assembling parts made of dissimilar materials.
Additive manufacturing processes, commonly referred to as 3D printing processes, are used to form objects by sequentially depositing material with a printer and subsequently hardening the deposited material to complete the part manufacturing process. A powder form metal or polymer material and binder may be deposited by a printer head on a 3-D printing machine bed that is later melted to soften the material and then solidified by applying heat or light. Different methods of solidifying the printed layers include selective laser melting (SLM), direct metal laser sintering (DMLS), selective laser sintering (SLS), fused deposition modeling (FDM), fused filament fabrication (FFF), stereo lithography (SLA), and laminated object manufacturing (LOM). Another approach is to extrude thin layers of molten material with an extruder that is later solidified.
Additive manufacturing processes utilize computer aided design (CAD) data or data from another electronic data source to produce 3D objects. The CAD is provided to a 3D printer to produce objects directly from the CAD data.
Prototype automotive parts have been made with additive processes but the time required to produce parts in high volumes has prevented the adoption of additive processes for manufacturing. Potential advantages of adopting additive manufacturing processes include eliminating the need to develop stamping die sets and welding or joining robots and tools to join multiple parts of an assembly together.
The above problems and other problems are addressed by this disclosure as summarized below.